The Los Angeles County Coroner's office has confirmed that rapper Pimp C -- one half of UGK -- died of an overdose of prescription-strength cough medicine used when making the drug cocktail dubbed "syrup."

According to assistant chief coroner Ed Winter, the rapper suffered from sleep apnea, a disorder that causes blockage of a person's airways during sleep. The illness coupled with the large dose of cough syrup is responsible for the death of Pimp C, whose real name was Chad Butler.

Three 6 Mafia, along with UGK, brought attention to the drug combination of codeine and promethazine with the 2000 single, 'Sippin on Some Syrup.' Butler was found dead at the Mondrian Hotel in West Hollywood, California, on December 4. He was 33. Read the full story.